Clothianidin

Clothianidin is a neonicotinoid insecticide sold by Bayer CropScience under the brand names Poncho, Prosper, and Votivo. Clothianidin and other neonicotinoids are suspected as the cause of Colony Collapse Disorder (CCD), a phenomenon in which entire colonies of bees mysteriously and rapidly die off. Clothianidin is a "systemic" pesticide that is applied as a seed treatment and subsequently spreads to all parts of the plant. It was first used in the U.S. on corn and canola in 2003. In December 2010, following a leaked EPA memo, pesticide watchdog groups and beekeepers called on the EPA to issue "an immediate stop-use order on the pesticide while the science is redone, and redesigned in partnership with practicing beekeepers."

Clothianidin Scandal Timeline
In the U.S., the EPA does not allow a pesticide on the market until it is registered. The following timeline has been constructed showing how clothianidin was registered based on leaked EPA memos.


 * February 2003: A leaked EPA memo from February 2003 shows that EPA scientists initially called for "a complete worker bee life cycle study (about 63 days) . . . as well as an evaluation of exposure to the queen" prior to allowing Clothianidin on the market, as they worried it "has the potential for toxic risk to honey bees."


 * April 2003: A second leaked memo reiterates concern about clothianidin's toxicity to bees, but now agrees to conditional registration, with the requirement of a "chronic life cycle study that evaluates the sublethal effects of clothianidin to the hive over time." The conditional registration allowed the product on the market, but required the study in order to complete the registration. The study was to include "an evaluation of two complete life cycles (~130 days), including egg, larvae, adult stages, and mortality of the honey bee colony;" "an evaluation of the exposure and effects to the queen during these life cycles;" "provide clothianidin residue analysis of the stored nectar, honey, and pollen at the beginning of the study, at periodic intervals during the study and at the end of the study;" and "the study must include replicated data with statistical comparison to controls." Following the study, the EPA planned to asses whether a strong warning label on the product would be required. They recommended the following text for the label: "This compound is toxic to honey bees. The persistence of the residues and the expression of clothianidin in nectar and pollen suggests the possibility of chronic toxic risk to honey bee larvae and the eventual stability of the hive."


 * May 2003: Clothianidin is given a conditional registration for use as a seed treatment on corn and canola, with the study to be performed by December 2004.


 * March 2004: A third leaked memo shows that Bayer requested and was granted an extension until May 2005 to complete their study and permission to make changes to the study. Before, they were to perform the study in the U.S., but now they were given permission to do the study in Canada on canola. Canola is a minor crop in the U.S., compared to corn. Corn is a major source of pollen for honey bees.


 * August 2006: Bayer completes and turns in its study, over one year after the May 2005 deadline.


 * November 2007: The EPA reviews the study and deems it "acceptable." Clothianidin's registration for seed treatments on corn and cotton is completed.


 * 2008: Natural Resources Defense Council sues the EPA over their failure to provide the study in response to a FOIA request. Also, beekeeper Tom Theobald finds the missing study on the internet, along with the several EPA memos about the registration of clothianidin.


 * July 2010: Theobald writes an article about the memos and the study for Bee Culture. He says, of the EPA's assessment that Bayer's study is scientifically sound: "Scientifically sound? If you’re in 4th grade perhaps, but certainly not if you have a Phd after your name. They should be embarrassed, this makes a mockery of science."


 * November 2010: In a memo to the management the EPA's Environmental Fate and Effects Division, Joseph DeCant (an EPA ecologist) and Michael Barrett (an EPA chemist) assess whether to register clothianidin for seed treatments for both mustard and cotton. They say: "Clothianidin’s major risk concern is to nontarget insects (that is, honey bees). Clothianidin is a neonicotinoid insecticide that is both persistent and systemic.  Acute toxicity studies to honey bees show that clothianidin is highly toxic on both a contact and an oral basis." They also note the previous study, saying: "A previous field study (MRID 46907801/46907802) investigated the effects of clothianidin on whole hive parameters and was classified as acceptable.  However, after another review of this field study in light of additional information, deficiencies were identified that render the study supplemental.  It does not satisfy the guideline 850.3040, and another field study is needed to evaluate the effects of clothianidin on bees through contaminated pollen and nectar.  Exposure through contaminated pollen and nectar and potential toxic effects therefore remain an uncertainty for pollinators."


 * December 2010: Theobald and Pesticide Action Network obtain the November memo and take the issue public. Pesticide Action Network and Beyond Pesticides issued a joint statement to the press, "calling for an immediate stop-use order on the pesticide while the science is redone, and redesigned in partnership with practicing beekeepers."

External resources

 * Factsheet for Clothianidin, U.S. EPA.
 * Clothianidin Conditional Registration Timeline, Pesticide Action Network North America
 * Memo: Clothianidin Registration of Prosper T400 Seed Treatment on Mustard Seed (Oilseed and Condiment) and Poncho/Votivo Seed Treatment on Cotton, U.S. EPA, November 2, 2010.

External articles

 * Ariel Schwartz, Beekeeper Who Leaked EPA Documents: "I Don't Think We Can Survive This Winter", Fast Company, December 13, 2010.
 * Jill Richardson, Leaked Memo Sheds Light on Mysterious Bee Die-Offs and Who's to Blame, Alternet, December 10, 2010.
 * Tom Philpott, Leaked document shows EPA allowed bee-toxic pesticide despite own scientists’ red flags, Grist, December 10, 2010.
 * Ariel Schwartz, Wik-Bee Leaks: EPA Document Shows It Knowingly Allowed Pesticide That Kills Honey Bees, Fast Company, December 10, 2010.
 * Tom Theobald, Do We Have a Pesticide Blowout?, Bee Culture, July 1, 2010.
 * Bees “restored to health” in Italy after this spring’s neonicotinoid-free maize sowing, Youris.com, June 26, 2009.
 * Chuck Benbrook, Prevention, not profit, should drive pest management, Pesticide News, December 2008.
 * EPA Hides Data on Pesticide Link to Bee Die-Off, Society of Environmental Journalists, September 10, 2008.